from math import sqrt
x1, y1, x2, y2 = map(float, input().split())
r = sqrt((x2 - x1)**2 + (y2 - y1)**2)
print(r) from math import sqrt x1, y1, x2, y2 = map(float, input().split()) x1 map(float, input().split()) map float input().split() ().split () input split y1 x2 y2 r = sqrt((x2 - x1)**2 + (y2 - y1)**2) r sqrt((x2 - x1)**2 + (y2 - y1)**2) sqrt (x2 - x1)**2 + (y2 - y1)**2 (x2 - x1)**2 x2 - x1 x2 x1 2 (y2 - y1)**2 y2 - y1 y2 y1 2 print(r) print r x2, y2 = map(float, input().split()) map(float, input().split()) x2 y2 = map(float, input().split()) map(float, input().split()) y2 y1, x2, y2 = map(float, input().split()) map(float, input().split()) y1 r = sqrt((x2 - x1)**2 + (y2 - y1)**2) sqrt((x2 - x1)**2 + (y2 - y1)**2) r x1, y1, x2, y2 = map(float, input().split()) map(float, input().split()) x1
from math import sqrt
x1, y1, x2, y2 = map(float, input().split())
r = sqrt((x2 - x1)**2 + (y2 - y1)**2)
print(r)